Pharmacosiderite Mineral Data

General Pharmacosiderite Information

Chemical Formula:

KFe+++4(AsO4)3(OH)4•6-7(H2O)

Composition:

Molecular Weight = 873.38 gm

Potassium 4.48 % K 5.39 % K₂O

Iron 25.58 % Fe 36.57 % Fe₂O₃

Arsenic 25.74 % As 39.47 % As₂O₅

Hydrogen 2.08 % H 18.56 % H₂O

Oxygen 42.13 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

KFe³⁺₄(AsO₄)₃(OH)₄•7(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1813

Locality:

Link to MinDat.org Location Data.

Name Origin:

From the Greek, farmakon for "poison" and sideros for "iron."

Name Pronunciation:

Pharmacosiderite

Synonym:

ICSD 27302

PDF 34-155

Pharmacosiderite Image

Images:

Arthurite Pharmacosiderite

Comments: Altered rhyolite vug lined with brilliant apple green arthurite and cubic green crystals of pharmacosiderite.
Location: Majuba Hill Mine, Pershing County, Nevada. USA. Scale: 2.7 x 1.7 cm.
© John Veevaert

Images:

Pharmacosiderite

Comments: Translucent yellow-brown cubic Pharmacosiderite crystals.
Location: Wheal Gorland, Saint Day, Cornwall, England. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Pharmacosiderite Crystallography

Cell Dimensions:

a = 15.961, Z = 8; V = 4,066.12 Den(Calc)= 2.85

Crystal System:

Isometric - Hextetrahedral H-M Symbol (4 3m) Space Group: I 43m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 4.61(1), 8(0.9), 2.408(0.8),

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Forms: ( 1 0 0) ( 0 1 1) ( 1 1 1)

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Physical Properties of Pharmacosiderite

Cleavage:

{100} Indistinct

Color:

Olive green, Emerald green, Reddish brown, Yellowish brown, Honey yellow.

Density:

2.8 - 3, Average = 2.9

Diaphaneity:

Subtransparent to subtranslucent

Fracture:

Brittle - Sectile - Brittle fracture with slightly sectile shavings possible.

Habit:

Blocky - Crystal shape tends to be equant (e.g. feldspars).

Habit:

Crystalline - Coarse - Occurs as well-formed coarse sized crystals.

Habit:

Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).

Hardness:

2.5 - Finger Nail

Luminescence:

Non-fluorescent.

Luster:

Adamantine - Resinous

Streak:

yellowish green

Optical Properties of Pharmacosiderite

Gladstone-Dale:

CI meas= 0.055 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.038 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2432,KPDmeas= 0.239,KC= 0.2528
Ncalc = 1.71 - 1.76

Optical Data:

Isotropic, n=1.693.

Calculated Properties of Pharmacosiderite

Electron Density:

Bulk Density (Electron Density)=2.77 gm/cc
note: Specific Gravity of Pharmacosiderite =2.85 gm/cc.

Fermion Index:

Fermion Index = 0.005633139
Boson Index = 0.994366861

Photoelectric:

PE_{Pharmacosiderite}= 25.35 barns/electron
U=PE_{Pharmacosiderite} x r_electron= 70.15 barns/cc.

Radioactivity:

GRapi = 62.69 (Gamma Ray American Petroleum Institute Units)
Concentration of Pharmacosiderite per GRapi unit = 1.60 (%)

Estimated Radioactivity from Pharmacosiderite - barely detectable

Pharmacosiderite Classification

Dana Class:

42.08.01.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.08)where (AB)7 (XO4)4 Zq ï¿½ x(H2O)

(42.08.01)Pharmacosiderite Group

42.08.01.01 Pharmacosiderite KFe4(AsO4)3(OH)4•6-7(H2O) I 43m 4 3m

42.08.01.02 Alumopharmacosiderite KAl4(AsO4)3(OH)4•6•5(H2O) P 43m 4 3m

42.08.01.03 Bariopharmacosiderite BaFe4(AsO4)3(OH)5•5(H2O) I 42m 4 2m

42.08.01.04 Barium-alumopharmacosiderite? BaAl4(AsO4)3(OH)5•5(H2O) P 43m ? 4 3m

42.08.01.05 Natropharmacosiderite (Na,K)2Fe4(AsO4)3(OH)5•7(H2O) P 43m 4 3m

Strunz Class:

08.DK.10 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DK -With large and medium-sized cations, (OH, etc.):RO4 > 1:1 and < 2:1

08.DK.10 Alumopharmacosiderite KAl4(AsO4)3(OH)4•6•5(H2O) P 43m 4 3m

08.DK.10 Barium-alumopharmacosiderite? BaAl4(AsO4)3(OH)5•5(H2O) P 43m ? 4 3m

08.DK.10 Bariopharmacosiderite BaFe4(AsO4)3(OH)5•5(H2O) I 42m 4 2m

08.DK.10 Barium-zinc-alumopharmacosiderite* (Ba,K)0.5(Zn,Cu)0.5(Al,Fe)4(AsO4)3•5(H2O) I 42m 4 2m

08.DK.10 Pharmacosiderite KFe4(AsO4)3(OH)4•6-7(H2O) I 43m 4 3m

08.DK.10 Natropharmacosiderite (Na,K)2Fe4(AsO4)3(OH)5•7(H2O) P 43m 4 3m

Other Pharmacosiderite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Pharmacosiderite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - Franklin Minerals(Dunn)
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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Print or Cut-and-Paste your Pharmacosiderite Specimen Label here :

Pharmacosiderite

KFe+++4(AsO4)3(OH)4•6-7(H2O)
Dana No: 42.08.01.01 Strunz No: 08.DK.10
Locality:

Notes:

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